Processes, such as those in an enterprise, are typically captured in partially ordered flows. Each instance (or execution thread) is a totally ordered task list. While total-order unifies how a person executes a single task, it can introduce inefficiencies during multi-tasking activities. In many instances, tasks (within a process) can be executed in an out-of-order or flexi-order fashion. Note that “flexi” is used herein as shorthand for “flexible.”
Traditional process models are quite rigid in encoding process flows. Specifically, current models are good at capturing partially ordered flows. A process diagram would basically say that Task A should be done before Task B. Additionally, branches, merges and decisions allow for different paths through the process to be followed.